SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ab38bc6b7c71f2565fcf36e15fa13ca36fd843134f16b879c9be77fa028cec5' 
  AND token = 'NugMwOwjjlWVDhJlYDkGSrQeAR5mJ8kYCSeQDDNpR/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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