SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b3932b772a61dcd7353876558fa57e9f60e41ecc702f73f194ed78737419b41' 
  AND token = 'ArvgC9SJvxOjNoxsWWTncgkVS8fVE4FXg4BdJcfFTqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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