SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f7c65cef81a6ee1c4eff086fc71517400a55420e98d2aac185813890f332d7' 
  AND token = 'YK6JOR6dgoc3DkFiQOty/r/cq2PnkzShfmwL1nPDZbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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