SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cb329c903557a102f87dcd82554c65bde6a654a8767521d61e8876270519880' 
  AND token = 'xJLfQ8khy/qlXlnzGJGk7mv2h0f/ikxlo9NB+8zqfFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00135

JSON explain

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