SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8e10e0a971981bdd9ef11071a1ad01aeffd9a0cb5a0767a82a5c6550d351f3f' 
  AND token = 'RXdESCmYfblXyc55re19fZyvjI7aBh29x9Swnk99UDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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