SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '997fcb9182d06f3ca93e3038189cdab7b8c0fb24a2b29ab04666e79e7dc81d21' 
  AND token = 'gXE9dNjxhUft8CtkKD57IoQbEYbcILFU4rgwbs3ecaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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