SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '135a4447649ef791d2185981126398cad9c7c9868e1750a54d8a435d4cead958' 
  AND token = 'eqE02J7BzDha6jK1eAWH0AAe+vWa7he/3v2rc7QF560=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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