SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2e3020655c83e503c19aab72de670960dc1d75cd1b0db5701f09d2ce8a667dc' 
  AND token = 'GkGG8SYu5MUQweMmgZU6rcsQUuBTCxXD8JQQLsieQvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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