SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9048621f4d992b6c09214191425868a88fe0edd806aab5a8a210acbe8024966' 
  AND token = 'CXVm0eYrID19u7cTGQhYlKasIUQTh+1/4SyrZCDkSas=' 
  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"
    }
  }
}