SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff4014f2c1cab05ff9085a8fb49d564707a6bb7f970416813337ed640f7de159' 
  AND token = 'glhqH4Y/VVgegwuJDIhEIpvfsbmKvNt3wmeTUKNuhRI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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