SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f3fd1df1f5dbc2e1c43ae712b64b5233989c44690034475b4da684ea44b4e071' 
  AND token = 'VanpiJw9+vnMYnNPnoiqtPLQqcGT5K8F3obIPO0+XBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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