SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7baa372e0e8bdf6d6ba669d98323b3f9f9e385229013be33fb6aa09613c9848b' 
  AND token = 'noZFkvx+PD6Re028ZYNW81/xhJPA1HaVnVBQMTWq8uY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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