SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6885c111d8e1b690aef178ecc83c72a504dcee47a7b8ef431277a9bac22caa5c' 
  AND token = 'JRr2vKEijyYIpzxPIXuYaQ2DQPm6GixAu5R8CZdo7Ww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}