SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33b9c5217748ad9ff84268198c992944591f91e09c772b318ce19b1e14d2290a' 
  AND token = 'cuYa0GFiDvgHVQpe4+xTA8gZ2LdPRB3JIPvizFj+fZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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