SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b3dbcfb8f031d1e13f22ab47eb6107ee852bac1c39b2315e4952586200d7b705' 
  AND token = 'J6k70h6pxhO4iHUFumJ8jNYScOE56m1fwxA2jRLWz1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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