SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c855337944c5336ba40f214c80cf1dd602416737a6556072cf697c49c96efd76' 
  AND token = 'wPrIWG2poEqh/kcRhEZmtiwu7EjbDwkJYqzOClvfP04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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