SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7431f72cd9262849718c1a797f985b411dc28d9a972e1a985d028ba1116bd3f8' 
  AND token = '2KVm+LFmosxWJQbT+XVNAJ30rV6UOSPPqyrKZ+IEXg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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