SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95cc9bdb46d61c6a72aaea6df57d17aebf6510f307949b90f302729688e19951' 
  AND token = 's9lCHD/tZb5Ndtx+0SEbF6HEQIWMsg2BxsvBLaQNsf8=' 
  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"
    }
  }
}