SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57bfecda15f9fdcaa0f297e478059440e42ee5523c9ea40a28bc034160357f79' 
  AND token = 'wP0JsuYscFhPQ/KXr/hBZEVVfROp6IXsv7055dLSfH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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