SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38450b92a91a0b284019fe0ed800cd48aacd9183862828fb5185d29f51d40bee' 
  AND token = 'yLkvdSBh8sRN48VP0sglgk/Mv4qs93Eexa/asGDOOZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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