SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9a5568d635c11b986580fa6051edd14aaf282cd11181ce7d4d512fc5a5ad964' 
  AND token = 'ej5mYHEVXPMb10HL/0ftZbGHTWbaFWYoCtwro1FmNvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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