SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9da0726eaeb16fb49180cac7a88f03a3b07fa5623e25116a068ca6e4bf657a21' 
  AND token = 'g7GxdJWT+YjVkzXLQKkp1Pt4m8b2G6X41yQf8gk5QLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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