SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49f1caa20cb4f308759c604f65991a3232a2ff27b88137a5c8b6ae03f5131024' 
  AND token = 'K+cx1qKX8YTMfl9tniY5p8vLeeDUmqRQ76Q5nq3xqH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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