SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3edd73143adb69980c96814c7685e664f11941f16f08b897edcb16fb52f824a' 
  AND token = 'xrfIwxrXHFdsXcZDjGvZfsUTNR6kxV/o8ybc26+5M5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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