SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93d2743a6b826cd72a540cfeaf0ff6181ce7339cb41f2d1aefd36bc74f8e0cd3' 
  AND token = 'nssTlmZ+2RcoIqx+hsk4Czk9htmSghMQEgXobtwqw88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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