SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17ab62aedf51e12b7e0efacf9456337550193f9320951d75d87356973b856d00' 
  AND token = 'fSvSUHHjNHwdPnLu6P2J+YLYDzX6pxbnmRlHXg+reVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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