SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60b99cfb49412fb3652f0318ee96b42e90d0c377f3312f9142de5b5fed4fcedf' 
  AND token = 'xmzPVfDiuWJ+Q0hjGb/cqMV2yRm12nbvHC/dnmZGdJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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