SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fed1c40f2e60957be793a548a7a1029e1a9b96f5d999ab3b791b2a6ac1905dd3' 
  AND token = 'LjcfWdDErKh0BdEDw6TardGDYsHpZnlipdaakRtK7EQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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