SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd5345861dd647bb22bc85c832ea881927ec5ccd5f4e77d3cc6c75a8deb2d9c53' 
  AND token = 'RH/oMw9S09E+m4IUydaQxhFuf3i7WQvkCpvSEkAjcyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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