SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f45e454068137d4d20ca562e09c21eac8c25c6e8b0e975b96ba5e2a78654182' 
  AND token = 'YVCs6j69jHf+lswtR+/q5K4XoFpp51B+yLAZo7gU6RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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