SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68125842dfb1856b5d99694a74a3544bd27a66a36ac9a85b7c2d91effe92315d' 
  AND token = '2B6iKIKjhOqTwoCJTBB+qIL6m3e7ozkhtjONUE3V6mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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