SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '88706e2df0568d5c80159f4df5fadf7f41862817a480cf6f6320996b01e40f02' 
  AND token = 'jtovjuKRmUeFGkJbOn8yNqMW8PLpZ1C94PpIoqR4GuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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