SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5418f9d9714810909bc7af9651b82d415c495b2accd88e25db60c35f67b56f7a' 
  AND token = 'r2gOF/eBJIYAvd1bfJM3fGEoqPqTnyF5rLEwDhgLfxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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