SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc04fb7e0243148303109d0db1c84bf39e67ac8377ffd624b3097867cc29a53e' 
  AND token = 'WtdrlxVMIvfuCksTkz7viNRpIMGUFCkKiz2SKrwG8BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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