SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f74763acaa5667c68a8c280c2c19615ce85a79d74ebb2bf62b3df724d2fb6d95' 
  AND token = 'oyRPZn2kGbm3tnai2XjOpKRQWEA1GnpHrFuzthZdywU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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