SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebffe8b1f2ee365b284a83f4455aa0ab71613ba01862a8b920340764bcea1359' 
  AND token = 'RsHkeRaTdCKLgI88F12OshgFKJWZ3hGATOQsLIAPB2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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