SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4e64aa5a65e2ab78ecc4392bca5c5a60380362936a4b98326d5751a497b1524' 
  AND token = 'wu+hd93eVQgFdRszDqhghImCQwjlJqD3NVg/eomF8PE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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