SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf883ca9aae580934684d10ca899af11251763035cbf4ab7f5912e6c68111bb1' 
  AND token = 'bQl5FU3YeOhKtArQZaU6krVCtCn5kcNSkNfnT9QLDjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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