SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af39b9fa005edfe191f471a23156269cff3b2f48437980985956f964ebd471ab' 
  AND token = 'n6PDyHnWFxA0pmK8dJih7T1ZhGgCVWbkvmbQf8ibdk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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