SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea6f164733c09a0bf1e6611d7b76f9ab3b98976dbc464ad2dec6e7b671c08f79' 
  AND token = 'QDvgqdI84DKYO0zy/4xvn/ZZUBHoDLBLhjzy+DOxKRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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