SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee8b4a113cb4118e4c0fe8683f2755cbc73cf22657caf51c536b94d7076606fa' 
  AND token = 'SKcY2VbC5Cqhp7ZQEPuq+UVWoH3xzvfdG1OCk4797Zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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