SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd4290e286ea68fc7306b8606147c05dce932a570122752c64b5d146d85bcc2' 
  AND token = 'ZkASI5NvBmW15I9uZd8bGWcZWesqAc5KMXBuo0qbJjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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