SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47f819cd34c4c0b8fc74118095afb6efcd7ee53475db346113cf66f4723022f4' 
  AND token = 'TEOf1CfhkyFWbyrUQA8rwyZWm25W82L3j9XX9393gts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}