SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '156ac20795139742dd43e777cc882ebcf7fa7463996cd096eeea24f4d77baf22' 
  AND token = 'ctGuiaqKNkrukjSbrPsm/4mAEnjjrBPyI6VpYzRCsXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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