SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db7c6a0ab519d921ae05cbd7f2ceccf308fa2b040959701058146ef697a17bf0' 
  AND token = '9SWM+JHezkef2NEye5TJ4brt1EpnLdiV3FsIAl/JH/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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