SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9413d84ef158628a3a001c51f99938d7082085a43dce699211eb2ce00d4aeeaf' 
  AND token = 'yYNv/xstu4MdDIRXra7r/ODkVOLzmsmBngTmOuELauQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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