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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8275e5123ab33f6b7f78dd28ff04c16f95066d86ad5b80e9cf23e8d44bd93db5' 
  AND token = 'd2wIkjSU5WanRaL/5TTbp3vdBQ8DabuJzpD2bEaJW9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}