SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c08ffcdcd2713e6c2c47ddb8958f83e8bba899c8cfac8be88aa3d57e228c9686' 
  AND token = 'nc0HqNYnrYJzoor0+l85l7SoX6Ey16e6PhOwDDukDpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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