SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec5bfc1f4b4202030e41c6895e2b54135c9ef8da4baa01e199e775df1441172d' 
  AND token = '07/AVAzoyBNWFFhGEtGhPm7DggEKVyws9TEQJrGCVoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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