SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b99196940a4b86149280c2789a36ff5ace69ff101dbd40a82eca99a8888ee64' 
  AND token = 'ocisRp1yxCjYey9DQkPD4nFB6MVd9lFqjgtCGjNA68c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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