SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00bcbd937b752a2633dc0dfaf45729901c4c2195aa78d92a117115799caac076' 
  AND token = 'JtImXRdnUudxDFUc3pZtamnzT8/qhcKDVJPCz7X0HI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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