SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '77a208663cea4b028352a4f6b1551dc84cb9f8a90e902594baec4e537e872fce' 
  AND token = '6AtneOJCmhOweq0M07JQMyFKY8SM51zZnpEDjLG9WjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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