SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef910402a22694e2a6d0e386a3d3a3e89f2429aab0a278895ad208efc1d5d8e2' 
  AND token = 'WSROlUvxn3lp2rFqI0Izk/X35wBBWLeuIi2Fn6D9M5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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