SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c23142613245f19de7eb3bc0bbf40161fb0efd9982b863c49de974501ea0db0d' 
  AND token = 'bG1NSAgLck/+06eZMj/mGKQTWRpyZyqKjkFqyyPBf+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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