SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f38c387368c52824a824e7fd9f701df919ae57996138a0fe4605fef218ad0698' 
  AND token = 'y5TRcBs1BczeNUuN5cOuAM9NH6VpJw0pnmA3oPovtXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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