SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b6afad47e392b58d1416374eca5a728d9fc89212b153a2c03d69e803ec63126' 
  AND token = 'EHZOn/+DvX4HiueuWSwdDDmz4N4hWDPAmclSP93xXcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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