SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '247c844f3f90cee7de953b6b05a75645af177128e61fecce3832918ace932939' 
  AND token = 'PPiqICgGXP1hpWONjjXBym/3vUavHx+WYpTARKdutVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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