SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89a607fcecdfda983a939f094d9e3e94d228233c3c8f58c5d9ca08fc6d9d1ba9' 
  AND token = 'ZwvHrp7ajWFzvd30NCIFUqDbAr1LqbtUA7S5aJd9c5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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