SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fbf3f67e10f9e8eee9c90f034c135619c9769b7e9154246790d1f541c4313ee0' 
  AND token = 'RySK8RZ57czsA/2UtjyvTL6qm4cfOYPoOPxg/+TgOnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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