SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5bf3da29fb20086b0ab52317d4cb79ada2b75287eb109fb28fda76c90133a75' 
  AND token = '8Vk6p8ESV8CrINueE1gCWQ/JezTJ5ZirKPUx/uvvVEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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