SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dc703ee355605dcac12f6d6c32fba9fe79f53c08ea2258b736cca4dc50d845d0' 
  AND token = 'a/oWKCMgQ7H7RJu6pZ1WYqFa9jhVqTPa2AhbXk1nfIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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