SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c41d70f4e1fc505e13f34ad4ca00b10829028b0bc5ab3ced6c5bed19936af2' 
  AND token = 'u7Z1/8vZXRX8oyqYTOdZYlga+i8UCXgG6JPYnfT88VA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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