SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c65b53210145ab636d3eb272bc3a00b59ff449a911f604b38c06ea365257c13' 
  AND token = '4DSERFgHU+Yt8Pu7ZrRTu1vBqdGIL3jVGJ9foURBOe0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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