SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9192f58832a18df0027c21ccb8db5f6c12de645c343bec7a3c6cb0cd9aab7b61' 
  AND token = 'QFvgRMNLqcZ55biu96oleWA3M7FXdlqka9x3gx4khiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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