SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bf7b9ef94d2a3fac9a2b020c63daab5ada7bc08f4b024a902ae3392c3eda13c' 
  AND token = 'FKuR6qDE2a8ai8T36OoI/o+vpyWKERRCkggzhTxNJak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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