SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '50424c353b8c0556fbe9ea174391b30b204962a68657ec59b8ef8f11192240e3' 
  AND token = '1J+aoaX/zAZGWxMwko/v5YAV39ifqDPpDHewMf0gz7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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