SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac9cf25759189f2f66639dce051c8150c6f281a3d974596811893798e5508505' 
  AND token = 'ZEKWe1sLBC1T0d6+93boAsMOb5StusMRLoNQGarhg+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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