SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'de8fd100bcbf4f9e1cb0b36514eb5a197428c847380a60ddeaa636be83273395' 
  AND token = 'VPIUHEX2U14rhW1qGCE0FAoHdA9paYOGBkMYCPmH8NM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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