SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1f88df126ac467100795ac812ef7bf89ee7f1d640cc0eabe0f87226cf1c356b4' 
  AND token = 'YO6DY01amXvbzO4yVl6ro5BlLcN+bTYws9kJhQojaJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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