SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37cc25362b124ea5a725d3b54ef2e9ac401acd3214fa61fae71097cbdda96c5f' 
  AND token = 'Cla2q1qy2NKxenHVtJqcSH3w7SPf2m9BniXlMquJFok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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