SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3bb905c6853bfee409dba3d7a9c1f80d044fc478067fa812d9e1659249742f0' 
  AND token = 'wtLXVXLL8Ft8RxO7GYygmX1uwyehSk7SkM5Vt59EB3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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