SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a568d85940f0d094aa47ba5349323be712c7bf78a774e0efaa515477e7905a35' 
  AND token = 'jYW9JqPJfp0YIK35/TwQY8biIIFsKCpjMH/2VNkDD8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00560

JSON explain

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