SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f09b3da298b2fcdccd0c01f4ee40255af293ea4943d1e8725a8658333a99205' 
  AND token = '7U3RTC4GxKFvFwk6NYdQhrz70X6TQLuUYWOYVqB6AAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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