SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fef2ffc095883d593fa9c6fd24997d5a097ad94e43766d6123deb7f6c295a83' 
  AND token = 'LsWKyPeBTTRSQbnOSZggdizWsIKtomZ8oAZjRftDELk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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