SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c14f51b5fd76a5bcbacce31b67bd0f54a0776f1e07199910621bfd4584dcd9e5' 
  AND token = 'ZZi/Xhp7s0CQrYXFQVSoyLnQsVFb15kw553MlPxoCk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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